Remand prisoners awaiting trial and those convicted but posing a low or medium risk will be fully separated from inmates presenting the greatest danger, like dissident republicans, at Maghaberry in Co Antrim.

Minister David Ford also said there was a "convincing case" for retaining Magilligan prison in the north west. Prison officers demonstrated at Stormont last week demanding that it be kept open.

Mr Ford said: "Following consultation, I have decided to proceed with the proposal to reconfigure Maghaberry into three mini prisons - for remand prisoners, low to medium security prisoners, and those prisoners requiring high security - as suggested by the Prison Review Team.

"Not only will this create operational efficiencies, but it will also allow Northern Ireland Prison Service (NIPS) to deliver better tailored regimes to specific groups of prisoners within Maghaberry, and will help to underpin and reinforce work to rehabilitate offenders."

He detailed his outline estate strategy for prisons at the Stormont Assembly on Monday.

"My intention is to create a discrete high-security facility within the main prison at Maghaberry, which would include provision for both separated (paramilitary) prisoners and those prisoners from the integrated population requiring high security," the minister said.

An independent report last year labelled parts of the Prison Service as ineffective and highlighted challenges posed by paramilitary inmates (who are already held in separate wings) and the rising general prison population. It said prison managers were overfocused on physical security, with excessive staffing levels and concessions to separated prisoners highlighting deficiencies in the regime for others.

Reviewer Dame Anne Owers recommended an early retirement scheme for long-serving staff and a recruitment programme to bring in fresh blood, which has been introduced. A string of prisoners have committed suicide while in custody and there have been repeated calls for mental health reform in prisons.

Mr Ford said: "There is a need to manage the difficult transition between prison and community, particularly for those prisoners who have received long sentences, if we are to achieve effective rehabilitation and reduce the risk of reoffending."